Eosinophilia: Experience of an imported disease unit in a pediatric tertiary care hospital

Background. Eosinophilia is a common laboratory finding among the pediatric population and may have multiple causes. Allergic disorders (most frequent among autochthonous population) and infectious diseases (more prevalent among immigrant patients) are considered to be the main etiologies. Objective. To determine the characteristics of patients with eosinophilia who were seen at an Imported Diseases Unit in a pediatric tertiary care hospital. Method. Descriptive retrospective study including all patients presenting with eosinophilia in the unit between January 2009 and December 2010. Results. Thirty-nine patients were included; 79.5% of them were immigrants. Sixty-nine point five percent had mild eosinophilia, 25.6% moderate, and 5.1% severe. A final diagnosis was reached in 59% of the cases (65.2% parasitic infection, 26.1% atopic disease, and 8.7% other causes). All patients with a final diagnosis received directed therapy. Among those, regression of the eosinophilia was observed in 93.3%. The area of origin was significantly associated with the final diagnosis (p<0.05); a higher prevalence of parasitic infections was found among immigrants (72.2%) than among native children. None of the parasitic species were found to correlate with a specific region. The time spent in the country of origin was not significantly associated with the probability of having a stool sample positive for parasites. Conclusions. Eosinophilia is a common finding that needs to be investigated, even when isolated, as it may be the first and only manifestation of a potentially severe condition. It is important to follow specific diagnostic protocols depending on the origin and characteristics of the patient.